This invention relates to a magnetic recording/ reproducing apparatus suitable for recording and reproducing two kinds of video signals for different aspect ratios of the screen and a conversion adapter unit suitable for converting a video signal for one screen aspect ratio into a video signal for the other aspect ratio.
In order to improve picture quality and live feeling as obtained with the existing NTSC television system, development of the wide NTSC system in which the aspect ratio of the screen (the ratio of lateral or horizontal length to longitudinal or vertical length) is enlarged has been evolved.
The wide NTSC system considers, to some extent, compatibility with the existing NTSC type television receiver set to allow it to receive video signals of practically acceptable quality.
As disclosed in Japanese Kokois JP-A-62-84684 and JP-A-62-84685, prior art wide screen television systems have been proposed wherein a multiplex video signal for an aspect ratio a.sub.1 of, for example, 16:9 in which video information concerning opposite left and right side portions (also called side panels) is time-compression multiplexed is transmitted in contrast to the video signal for an aspect ratio a.sub.2 of 4:3 of the existing NTSC type screen. In another approach, a signal for the a.sub.2 screen aspect ratio, by which top and bottom portions of the screen are blanked so that an auxiliary signal for resolution improvement is multiplexed at the blank portions, is transmitted.
With the wide screen television practiced in addition to the existing television system, co-existence of two broadcasting systems is,, realized. However, both the systems are essentially based on the NTSC system and simply differ in aspect ratio and hence, for example, the same VTR (magnetic video recording/reproducing apparatus) must be compatible with either of the two systems. More specifically, a signal for the existing system video-recorded on a tape must be reproduced so as to be normally displayed on not only the existing 4:3 aspect ratio monitor television but also a future monitor television having an aspect ratio of, for example, 16:9. At the same time, a signal for a future aspect ratio of, for example, 16:9 video-recorded on a tape must be reproduced so as to be normally displayed on not only a future 16:9 aspect ratio monitor television but also the existing 4:3 monitor television.
However, the aforementioned prior art references in no way disclose matters concerning VTR's, leaving behind the following problems which remain unsolved in connection with VTR's.
(1) When a signal for 16:9 aspect ratio video-recorded on a tape is reproduced and processed by the existing monitor television, the horizontal length of a picture on the screen is compressed relative to the vertical length and a picture displayed on the screen is so distorted as to be elongated vertically considerably.
(2) Conversely, when a signal for the existing 4:3 aspect ratio video-recorded on a tape is reproduced and processed by a future monitor television of, for example, 16:9 aspect ratio, the horizontal length of a picture on the screen is expanded relative to the vertical length and a picture displayed on the screen is so distorted as to be elongated horizontally considerably.